1. Field of the Invention
The present invention relates generally to printing apparatus and more particularly to carriage assemblies for carrying the print heads of high-speed serial printers.
2. Description of the Prior Art
High-speed serial printers are well known in the art and have been developed to accommodate the high output speed of information which can be delivered by high-speed data processing systems. Also, print heads which can accommodate high-speed electronics are well known in the prior art. For example, serial printers employing wire matrix ballistic impact print heads capable for providing multiple hard copies of information at relatively high speed are known. Such printers are characterized in that for each print cycle, the printer uses an array of wire styli to print selective combinations of dots serially onto the recording medium (e.g., paper) so that as the recording medium is moved laterally relative to the print head, successive print cycles generate alphanumeric characters or other informational indicia. Wire matrix ballistic impact print heads typically use a separate electromagnetic actuator for each stylus within the print head. Commonly, there are approximately nine styli in each print head such that the electromagnets are arranged in a circular pattern with the styli extending therefrom a substantial distance to convert the circular orientation at the actuators to a linear pattern at the terminating ends. As a result, the head has a relatively long neck portion.
As high-speed serial printers become more widely used and the demands increase for printing apparatus capable of accommodating larger volumes of information at faster rates, it becomes desirable to have improved carriage means for carrying the print head. For example, demands exist for a carriage that provides for rapid and easy installation of the print head so that the operator of the printer can rapidly and quickly remove and/or insert the print head for repair, replacement and/or cleaning. At the same time, it is necessary that the carriage be such that it can travel at very high speeds and withstand substantial impact as it carries the head laterally forward and in reverse directions across the print medium. It is also necessary that the head be secured to the carriage such that it does not shift in its position relative to the platen during operation. Furthermore, as the demands for data processing equipment continually increase, it is essential to develop printers which are economical and capable of mass production.